Abstract
AMI and coronary intervention in patients undergoing dialysis are associated with poor survival outcomes. Despite a downward trend in the overall incidence of MI, the incidence among young adults is on the rise. This is a retrospective study including patients from the Houston Methodist Young ACS-PCI registry. The cohort incorporates patients ≤50 years old experiencing type 1 MI and undergoing PCI between 2010 and 2022. The primary endpoint was 1-year major adverse cardiovascular events (MACE) (all-cause mortality, MI, and ischemic stroke). Secondary endpoints included components of MACE and repeat revascularization. Of 628 young adults undergoing PCI for ACS (median age 45 years, 23.6% women), 10.4% were on dialysis. Patients receiving dialysis were more often women (49.2% vs 20.6%, p < 0.001), Black (32.3% vs 16.5%, p = 0.009), and had more frequent cardiovascular risk factors. There was no difference in terms of ACS presentation. Angiographic characteristics were similar, but femoral access was more common in the dialysis group (98.5% vs 83.7%, p = 0.006). Patients on dialysis had longer hospital stays (4 vs 2 days; p < 0.001), major bleeding (10.8% vs 2.3%; p = 0.001) and higher 1-year MACE (26.2% vs 9.8%; p < 0.001), 1-year all-cause mortality (13.9% vs 3.4%; p < 0.001), and recurrent MI (13.9% vs 6.4%, p = 0.02). The risk of MACE (HR 2.7, 95% CI: 1.5–4.7) and long-term mortality (HR 4.9, 95% CI: 2.6–9.0) were higher among patients receiving dialysis. In conclusion, young adults on dialysis who undergo PCI for ACS face significantly higher comorbidity burden, bleeding risk, and long-term adverse outcomes, including increased MACE and mortality. Careful consideration is essential in this high-risk group and preventive measures should be undertaken to improve outcomes in this high-risk population.
Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with end-stage renal disease (ESRD), accounting for nearly 50% of deaths among those on dialysis. Acute coronary syndrome (ACS) is a common complication, occurring in approximately 2.9% of dialysis patients annually. , These individuals experience accelerated atherosclerosis, vascular calcification, and endothelial dysfunction, rendering them particularly vulnerable to ACS and adverse outcomes following percutaneous coronary intervention (PCI). ,,, Despite advancements in interventional cardiology and medical therapy, such patients remain at disproportionately higher risk for procedural complications, restenosis, stent thrombosis, and poor long-term survival. A graded relationship between serum creatinine levels and adverse outcomes following PCI has been well established. Even modest elevations in creatinine have been associated with significantly worse clinical outcomes after PCI. This underscores the role of renal function as a continuous risk marker in cardiovascular prognosis. However, while ESRD is clearly associated with increased risk, it is often assumed that young age confers some degree of protection. Young adults with ESRD on dialysis constitute a high-risk and underexplored subgroup in the context of ACS and revascularization. Traditional cardiovascular risk factors such as hypertension, diabetes mellitus, and dyslipidemia are frequently observed among adults under 50 years old presenting with myocardial infarction (MI). ,, In the setting of dialysis, however, nontraditional risk factors- including chronic inflammation, uremic toxicity, disordered mineral metabolism disorders, anemia, and volume overload- further accelerate vascular injury and compromise outcomes following PCI. ,, These mechanisms may both precipitate myocardial injury and contribute to poorer procedural PCI outcomes. The interplay between young age and dialysis remains poorly characterized, and data on this population are limited. The Houston Methodist Young ACS-PCI Registry offers a valuable opportunity to address these knowledge gaps by evaluating demographics, procedural characteristics, in-hospital complications, and long-term outcomes among young dialysis patients undergoing PCI for ACS. By comparing this cohort to nondialysis counterparts, the study aims to generate clinically meaningful insights that may refine treatment strategies and improve cardiovascular outcomes in this high-risk population.
Methods
Study population
The design of the Houston Methodist Young ACS-PCI Registry has been previously described. Briefly, this is a retrospective, single-center cohort study including young adults (18-50 years old) who experienced MI and underwent PCI at Houston Methodist Hospital, TX, between 2010 and 2022. All individuals presented with ACS, defined by documented symptoms of ischemia with either elevated troponin T levels, new electrocardiographic (ECG) changes, new regional wall-motion abnormalities, or angiographic evidence of intracoronary thrombus or coronary artery occlusion. All cases were adjudicated by a team of physicians, as previously described, using the Third Universal Definition of MI, only type 1 MI cases were included.
When patients underwent multiple revascularization procedures during the study period, only the first intervention was included for analysis. Patients were stratified based on their dialysis status before PCI, and those with a history of renal transplantation or unknown dialysis status were excluded ( Figure 1 ).
Study flowchart of patient selection and group stratification.
Data collection
The registry includes baseline demographic, clinical, and angiographic data, as well as medication history, extracted from electronic health records. Posthospitalization follow-up was conducted using institutional records, online resources (e.g., obituaries), and telephonic follow-ups.
Dialysis was defined as the requirement for chronic renal replacement therapy (CRRT), including either hemodialysis or peritoneal dialysis, at the time of PCI. ACS included ST-segment elevation MI (STEMI), non-STEMI (NSTEMI), and unstable angina.
Major bleeding was defined as a hemoglobin decrease of >3 g/dL, the need for a transfusion of ≥2 units of packed red blood cells, or bleeding requiring surgical intervention or intravenous vasoactive agents. The evaluation of risk factors, medications, laboratory parameters, and angiographic characteristics has been previously detailed.
Study endpoints
The primary endpoint was 1-year major adverse cardiac events (MACE), defined as a composite of all-cause mortality, recurrent MI, and stroke, along with long-term mortality after extended follow-up. Secondary endpoints included the individual components of MACE and rates of revascularization.
Data management
This study was approved by the Institutional Board Review (IRB) of Houston Methodist Hospital. Given the retrospective nature of the study, informed consent was waived. All data were handled according to institutional protocols for the protection of Patient Health Information (PHI).
Statistical analysis
Categorical variables are presented as frequencies and percentages and were compared using the χ2 test or Fisher’s exact test, as appropriate. Continuous variables are reported as means (standard deviation [SD]) or medians (Q1-Q3) and compared using the Student’s t-test or Mann-Whitney U test, as appropriate. Kaplan-Meier survival curves were generated to compare time-to-event outcomes between dialysis and nondialysis groups and compared using the log-rank test. A p-value < 0.05 was considered statistically significant.
All statistical analyses were conducted using STATA Version 17.0 (StataCorp, College Station, Texas).
Results
Baseline characteristics
Among 628 young adults, 10.4% (n = 65) were on dialysis at the time of PCI. Dialysis patients were more likely to be women (49.2% vs 20.6%; p < 0.001) and Black (32.3% vs 16.5%; p = 0.009) compared to nondialysis patients. They had a higher burden of diabetes mellitus (80% vs 35.0%), hypertension (98.5% vs 78.3%), heart failure (46.2% vs 15.8%), peripheral arterial disease (PAD) (32.3% vs 4.8%), and prior stroke (18.5% vs 6.4%) (all p < 0.05). Additionally, dialysis patients had lower hemoglobin levels at discharge compared to the nondialysis cohort (9.5 g/dL vs 13.2 g/dL, p < 0.001) ( Table 1 ).
Table 1
Baseline characteristics of adults with acute coronary syndrome undergoing percutaneous coronary intervention between 2010 and 2022
| Variable, n (%) | Overall (N = 628) | No dialysis (N = 563) | Dialysis (N = 65) | p-value |
|---|---|---|---|---|
| Age, years | 45 (40.0–50.0) | 45 (40.0–50.0) | 44 (39.0–49.0) | 0.61 |
| Female | 148 (23.6) | 116 (20.6) | 32 (49.2) | < 0.001 |
| BMI, kg/m 2 | 30.5 (26.8–34.7) | 30.5 (27–34.9) | 29.8 (25.0–33.8) | 0.20 |
| Race | ||||
| White | 411 (65.4) | 375 (66.6) | 36 (55.4) | 0.009 |
| Black | 114 (18.2) | 93 (16.5) | 21 (32.3) | |
| Asian | 55 (8.8) | 52 (9.2) | 3 (4.6) | |
| Family history of premature CAD | 90 (14.3) | 88 (15.6) | 2 (3.1) | 0.02 |
| Diabetes mellitus | 249 (39.6) | 197 (35.0) | 52 (80.0) | < 0.001 |
| Hypertension | 505 (80.4) | 441 (78.3) | 64 (98.5) | < 0.001 |
| Dyslipidemia | 517 (82.3) | 461 (81.9) | 56 (86.2) | 0.37 |
| Tobacco use | ||||
| Current smoker | 51 (8.1) | 47 (8.3) | 4 (6.1) | 0.90 |
| Former smoker | 48 (7.6) | 42 (7.5) | 6 (9.2) | |
| Heart failure | 119 (18.9) | 89 (15.8) | 30 (46.2) | < 0.001 |
| PAD | 48 (7.7) | 27 (4.8) | 21 (32.3) | < 0.001 |
| Chronic lung disease | 22 (3.5) | 16 (2.8) | 6 (9.2) | 0.008 |
| Cerebrovascular disease | 48 (7.6) | 36 (6.4) | 12 (18.5) | < 0.001 |
| Prior MI | 143 (22.8) | 124 (22.0) | 19 (29.2) | 0.18 |
| Prior PCI | 165 (26.3) | 146 (25.9) | 19 (29.2) | 0.56 |
| Prior CABG | 58 (9.2) | 51 (9.1) | 7 (10.8) | 0.80 |
| PCI status | ||||
| Elective | 332 (52.9) | 292 (51.9) | 40 (61.5) | 0.31 |
| Urgent | 169 (26.9) | 154 (27.4) | 15 (23.1) | |
| Emergent | 128 (20.4) | 118 (21.0) | 10 (15.4) | |
| Pre-PCI LVEF | 55 (50–60) | 55 (50–60) | 55 (41–60) | 0.09 |
| Pre PCI LVEF | ||||
| >50 | 319 (68.3) | 284 (69.4) | 35 (60.3) | 0.16 |
| 41–50 | 70 (14.9) | 61 (14.9) | 9 (15.5) | 0.90 |
| 30–40 | 54 (11.5) | 46 (11.2) | 8 (13.7) | 0.57 |
| <30 | 24 (5.1) | 18 (4.4) | 6 (10.3) | 0.05 |
| Laboratory values, median (Q1–Q3) | ||||
| Troponin preprocedure | ||||
| Troponin I (Preprocedure) | 0.52 (0.1–5.0) | 0.46 (0.1–5.1) | 0.91 (0.3–4.4) | 0.24 |
| Troponin postprocedure | ||||
| Troponin I (Postprocedure) | 27.0 (3.5–91.0) | 26.1 (3.4–91.0) | 41.8 (8.4–94.7) | 0.43 |
| Creatinine | ||||
| Creatinine Preprocedure (mg/dL) | 1.0 (0.8–1.2) | 0.9 (0.8–1.1) | 6.8 (5.2–9.6) | < 0.001 |
| Creatinine Postprocedure (mg/dL) | 0.97 (0.8–1.2) | 0.9 (0.8–1.1) | 7.0 (4.5–10.0) | < 0.001 |
| Creatinine at Discharge (mg/dL) | 0.97 (0.8–1.2) | 0.9 (0.8–1.1) | 6.7 (4.5–9.1) | < 0.001 |
| Hemoglobin | ||||
| Hemoglobin (Preprocedure) (g/dL) | 13.9 (12.2–15.2) | 14.1 (12.8–15.3) | 10.5 (9.3–11.6) | < 0.001 |
| Hemoglobin (Postprocedure) (g/dL) | 12.9 (11.1–14.0) | 13.1 (11.6–14.1) | 9.6 (8.5–10.8) | < 0.001 |
| Hemoglobin at discharge (g/dL) | 12.9 (11.1–14.0) | 13.2 (11.7–14.1) | 9.5 (8.5–10.9) | < 0.001 |
| Total cholesterol (mg/dL) | 174 (140.0–213.0) | 177.5 (142.7–214.2) |
147 (119.
0–178.0) |
< 0.001 |
| HDL (mg/dL) | 37 (30.0–45.0) | 37 (30.0–44.0) | 38 (28.0–51.0) | 0.16 |
| LDL (mg/dL) | 107 (76.0–140.0) | 110 (79.0–142.0) | 71 (49.5–106.5) | < 0.001 |
| Triglycerides (mg/dL) | 144 (101.0–234.0) | 147 (102.0–238.0) | 127 (84.0–191.0) | 0.07 |
| HbA1c (%) | 5.9 (5.5–7.9) | 5.9 (5.5–7.9) | 6.6 (5.7–8.3) | 0.11 |
| ACS Type | ||||
| STEMI | 110 (17.5) | 103 (18.3) | 7 (10.8) | 0.81 |
| NSTEMI | 435 (69.3) | 388 (68.9) | 47 (72.3) | |
| Unstable Angina | 84 (13.3) | 73 (13.0) | 11 (16.9) | |
| Medications at discharge | ||||
| Aspirin | 607 (96.7) | 546 (97.0) | 61 (93.8) | 0.10 |
| Clopidogrel | 431 (68.6) | 374 (66.4) | 57 (87.7) | 0.002 |
| Ticagrelor | 130 (20.7) | 126 (22.4) | 4 (6.2) | 0.02 |
| Prasugrel | 53 (8.4) | 50 (8.9) | 3 (4.6) | 0.47 |
| ACEI/ARB | 336 (53.5) | 305 (54.2) | 31 (47.6) | 0.55 |
| Beta-blockers | 526 (83.8) | 471 (83.7) | 55 (84.6) | 0.96 |
| Statins | 594 (94.6) | 536 (95.2) | 58 (89.2) | 0.14 |
Values are in number (%) unless otherwise indicated; IQR, interquartile range; BMI, body mass index; CAD, coronary artery disease; PAD, peripheral artery disease; MI, myocardial infarction; PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; LVEF, left-ventricular ejection fraction; HDL, High density lipoprotein; LDL, low-density lipoprotein; HbA1C, Hemoglobin A1C; ACS, acute coronary syndrome;STEMI, ST-elevation myocardial infarction; N-STEMI, non-STEMI; ACEI, Angiotensin-converting enzyme inhibitor; ARB, Angiotensin II receptor blocker. Bold indicates statistically significant results.
ACS presentation was similar between groups (p = 0.81), with 17.5% presenting with STEMI, 69.3% with NSTEMI, and 13.3% with unstable angina ( Figure 2 ).
Acute coronary syndrome (ACS) presentation in dialysis versus nondialysis patients.
Angiographic and procedural details
Procedural and angiographic findings are detailed in Table 2 . Right coronary dominance was observed in 86.2% of dialysis patients vs 85.6% of nondialysis patients (p = 0.33). Most patients had a single coronary lesion revascularized (70.8% vs 72.8%, p = 0.82) and received 1 stent (83.1% vs 78.0%, p = 0.68). The left anterior descending artery (LAD) was the most common culprit artery (56.2% vs 43.0%, p = 0.10). Dialysis patients were significantly more likely to undergo PCI via femoral access (98.5% vs 83.7%, p = 0.006) ( Figure 3 ).
Table 2
Procedural and angiographic findings in adults with acute coronary syndrome undergoing percutaneous coronary intervention between 2010 and 2022
| Variable, n (%) | Overall (N = 628) | No dialysis (N = 563) | Dialysis (N = 65) | p-value |
|---|---|---|---|---|
| Coronary circulation Dominance | ||||
| Co-dominant | 44 (7.0) | 38 (6.8) | 6 (9.2) | 0.33 |
| Left | 45 (7.2) | 43 (7.6) | 2 (3.1) | |
| Right | 538 (85.7) | 482 (85.6) | 56 (86.2) | |
| Number of lesions | ||||
| 1 | 456 (72.6) | 410 (72.8) | 46 (70.8) | 0.82 |
| 2 | 135 (21.5) | 119 (21.1) | 16 (24.6) | |
| 3 | 27 (4.3) | 24 (4.3) | 3 (4.6) | |
| 4 | 7 (1.1) | 7 (1.2) | 0 (0) | |
| 5 | 3 (0.5) | 3 (0.5) | 0 (0) | |
| Total number of stents | ||||
| 1 | 493 (78.5) | 439 (78.0) | 54 (83.1) | 0.68 |
| 2 | 111 (17.7) | 100 (17.9) | 11 (16.9) | |
| 3 | 14 (2.2) | 14 (2.5) | 0 (0) | |
| 4 | 3 (0.5) | 3 (0.5) | 0 (0) | |
| 5 | 1 (0.2) | 1 (0.2) | 0 (0) | |
| Culprit vessel stent location | ||||
| Left main artery | 23 (3.8) | 19 (3.4) | 4 (6.3) | 0.10 |
| Left anterior descending artery | 275 (44.4) | 239 (43.0) | 36 (56.2) | |
| Left circumflex artery | 67 (10.8) | 61 (11.1) | 6 (9.4) | |
| Right coronary artery | 153 (24.6) | 141 (25.4) | 12 (18.8) | |
| RCA branch (PDA/PLB) | 22 (3.6) | 20 (3.6) | 2 (3.1) | |
| Diagonal/Ramus | 31 (5.0) | 31 (5.6) | 0 (0) | |
| OM stent | 48 (7.8) | 44 (7.9) | 4 (6.3) | |
| PCI for multivessel disease | 98 (15.6) | 88 (15.6) | 10 (15.4) | 0.99 |
| Culprit vessel stent diameter (mm) | 3 (2.5–3.5) | 2.5 (2.0–3.0) | 2.5 (2.0–2.5) | 0.15 |
| Culprit vessel stent length (mm) | 12 (12.0–15.0) | 12 (12.0–15.0) | 12 (12.0–15.0) | 0.89 |
| Bifurcation Lesion | 52 (8.3) | 45 (8.0) | 7 (10.8) | 0.70 |
| Arterial access site | ||||
| Femoral | 535 (85.2) | 471 (83.7) | 64 (98.5) | 0.006 |
| Radial | 90 (1.4) | 89 (15.8) | 1 (1.5) | |
| Brachial | 3 (47.8) | 3 (0.5) | 0 (0) | |
| MCS | ||||
| IABP | 17 (2.7) | 15 (2.7) | 2 (3.1) | 0.69 |
| Impella | 6 (1.0) | 6 (1.1) | 0 (0) | |
| Preintervention TIMI flow | ||||
| TIMI-0 | 142 (22.7) | 135 (24.1) | 7 (10.8) | 0.09 |
| TIMI-1 | 26 (4.2) | 23 (4.1) | 3 (4.6) | |
| TIMI-2 | 72 (11.5) | 65 (11.6) | 7 (10.8) | |
| TIMI-3 | 385 (61.6) | 337 (60.2) | 48 (73.8) | |
| Postintervention TIMI flow | ||||
| TIMI-0 | 7 (1.1) | 6 (1.1) | 1 (1.5) | 0.66 |
| TIMI-1 | 4 (0.6) | 4 (0.7) | 0 (0) | |
| TIMI-2 | 10 (1.6) | 8 (1.4) | 2 (3.1) | |
| TIMI-3 | 598 (95.2) | 537 (95.3) | 61 (93.8) | |
| Contrast volume (mL) | 181.6 (130.0–220.0) | 180.5 (130.0–220.0) | 191.3 (135.0–230.0) | 0.26 |
| Fluoroscopy time, min | 19.0 (10.7–23.9) | 18.9 (10.5–24.0) | 19.8 (11.6–23.9) | 0.57 |
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